This disclosure is based upon, and claims priority from, International Application No. WO99/31625, filed Dec. 10, 1998 and French Patent Application No. 97/16412, filed Dec. 15, 1997, the contents of which are incorporated herein by reference.
The present invention relates to cards incorporating an integrated circuit or circuits (known as chip cards or smart cards) which are fitted with a device to guarantee they have not been used.
Many chip cards are used as a means of payment and are loaded with a stored value which is often formed by a sum of money or by a certain number of consumable units such as basic charges for telephone calls.
Chip cards of this kind are sold to the general public and it is necessary to give to the purchaser a guarantee that the card he is buying is xe2x80x9cvirginxe2x80x9d, i.e. that it has never been used and that the consumable stored value in it is at a maximum or in other words is equal to the nominal value of the card.
The way in which this is done at the moment is to pack the chip cards in a plastic film, which is generally transparent and sealed. This is not a very effective guarantee for chip cards which operate without contact, i.e. where the interface for exchanges with charging or payment units is an antenna built into the card.
What is more, it is often difficult to remove the card from the plastic protective and guarantee packaging because the packaging is difficult to tear. Also, the packaging becomes rubbish which the purchaser often throws away when he uses the chip card for the first time. And in addition the price of the plastic packaging and especially of putting it in place involves costs which are by no means negligible.
It has already been proposed that a guarantee label should be provided formed by a deposit of material which masks the interface of the chip card (an antenna or electrical contacts) and which can be scratched off. This scratching operation is not always easy nor is it very quick.
What is more, since the label is applied to the electronic module of the chip card, there is a risk that the scratching will damage the module, i.e. the working component of the card.
Finally, some residues may be left from the scratching and these may interfere with the operation of readers into which the chip card is inserted.
The basic problem faced by the invention is to provide a device for guaranteeing an unused state for a chip card which does not suffer from the above disadvantages.
To this end, the invention relates to a chip card (10) including an electronic module, which module is fitted with an interface for electrical and/or electromagnetic communications formed by electrical contacts and/or an antenna. It is characterised by the fact that it includes at least one guarantee label which is bonded to one of its surfaces and which can be unbonded by breaking the adhesion, said label being suitable for preventing said interface from communicating with the outside world.
The label is easy to fit to the chip card either automatically or manually and its cost price is low. The bond of which the adhesion can be broken enables the label to be pulled off easily in a single operation with no possibility of the chip card, and especially its working component, being damaged.
The label is small in size and if it is thrown away it forms a piece of rubbish which is far less objectionable than plastic packaging and one which is, moreover, quickly degradable.
Finally, the label does not leave on the chip card any traces which would pose a risk of interfering with the operation of readers.
According to another feature, the label is capable of showing whether it has been replaced after having been unbonded. To this end, means for indicating replacement may be provided which are described below.
In this way, any attempt at fraud is deterred and the purchaser is given a guarantee against any previous use of the card.
The label can prevent communications in different ways depending on the communication technique which is being used.
In one embodiment, where the communication is electrical, the label may comprise an insulating film which prevents electrical communications. This film extends over at least part of the contact interface.
In another embodiment, where the communication is electromagnetic, or even electrical, the label may include on its lower face a short-circuiting member which short-circuits the interface.
In another embodiment, where there is an interface comprising an antenna, the label comprises a metal film which forms a screen against electromagnetic communication with the outside world.
In another embodiment, once again where there is an interface comprising an antenna, the label may itself include an antenna circuit suitable for disrupting or diverting any electromagnetic communication with the outside world.
Where there is the short-circuit and an internal antenna, the card may include members for connecting the antenna to the short-circuiting member. The connecting members may be formed by metallised wells.
Where there is an interface having an internal antenna and contacts, certain of the interface""s contact areas may be used to connect the short-circuiting member to the internal antenna.
The means for indicating replacement may be produced in different ways.
In various embodiments, the label may include one or more premade cuts which cause it to be damaged when pulled off. The label may also be produced from a material whose appearance changes when it is subjected to mechanical stress. In other cases the label may also be capable of deforming plastically when it is unbonded. It may also include information on its outer face which is difficult to reproduce, such as a hologram.
In certain cases the information may comprise an identifying element. This information is specific to the chip card and makes its possible to detect that the original label has been removed and replaced.
Where required, the information present on the label is capable of being correlated by an algorithm with information present on the card or programmed into the electronic module.
In other cases, the information may form a continuation of information or a graphic motif present on the card such as a printed security element. The motif may be a simple mark which is laser-etched both onto the label and onto the card and/or module.
The label advantageously includes an unbonded area. What is obtained in this way is a gripping area which enables the label to be taken hold of properly in order to be pulled off. This unbonded area may be formed by a gripping tab.